Runoff modelling in glacierized Central Asian catchments for present-day and future climate

A conceptual precipitation–runoff model was applied in five glacierized catchments in Central Asia. The model, which was first developed and applied in the Alps, works on a daily time step and yields good results in the more continental climate of the Tien Shan mountains for present-day climate conditions. Runoff scenarios for different climates (doubling of CO2) and glacierization conditions predict an increased flood risk as a first stage and a more complex picture after a complete glacier loss: a higher discharge during spring due to an earlier and more intense snowmelt is followed by a water deficiency in hot and dry summer periods. This unfavourable seasonal redistribution of the water supply has dramatic consequences for the Central Asian lowlands, which depend to a high degree on the glacier melt water for irrigation and already nowadays suffer from water shortages

Modelling of hydrological response to climate change in glacierized Central Asian catchments

The arid lowlands of Central Asia are highly dependent on the water supplied by the Tien Shan mountains. Snow and ice storage make large contributions to current runoff, particularly in summer. Two runoff models with different temporal resolutions, HBV-ETH and OEZ, were applied in three glaciated catchments of the Tien Shan mountains. Scenario runs were produced for a climate change caused by the doubling of atmospheric CO2 as predicted by the GISS global circulation model and assuming a 50% reduction of glaciation extent, as well as a complete loss of glaciation. Agreement of the results was best for runs based on 50% glaciation loss, where both models predict an increase in spring and summer runoff compared to current levels. Scenarios for complete loss of glaciation predict an increase in spring runoff levels, followed by lower runoff levels for July and August. Model predictions differ concerning the degree of reduction of late summer runoff. These scenarios are sensitive to model simulation of basin precipitation, as well as to reduction of glaciation extent

On the long-range correlations in hadron-nucleus collisions

Long-range correlations between multiplicities in different rapidity windows in hadron-nucleus collisions are analyzed. After recalling the standard results in the probabilistic model, we study them in the framework of perturbative QCD. Considering interacting BFKL pomerons in the form of fan diagrams coupled to a dilute projectile, analytic estimates are done for very large rapidities. The correlation strength results weakly depending on energy and centrality or nuclear size, and generically greater than unity. Finally, we turn to the Color Glass Condensate framework. For a saturated projectile and considering the most feasible experimental situation of forward and backward rapidity windows symmetric around the center-of-mass, the resulting correlation strength turns out to be larger than unity and shows a non-monotonic behavior with increasing energy, first increasing and then decreasing to a limiting value. Its behavior with increasing centrality or nuclear size depends on the considered rapidity windows.Comment: 17 pages, LaTeX, 6 eps figures included using graphicx; v2: error in the CGC formula corrected, conclusions of the corresponding section changed accordingl

The B-L/Electroweak Hierarchy in Smooth Heterotic Compactifications

E8 X E8 heterotic string and M-theory, when appropriately compactified, can give rise to realistic, N=1 supersymmetric particle physics. In particular, the exact matter spectrum of the MSSM, including three right-handed neutrino supermultiplets, one per family, and one pair of Higgs-Higgs conjugate superfields is obtained by compactifying on Calabi-Yau manifolds admitting specific SU(4) vector bundles. These "heterotic standard models" have the SU(3)_{C} X SU(2)_{L} X U(1)_{Y} gauge group of the standard model augmented by an additional gauged U(1)_{B-L}. Their minimal content requires that the B-L gauge symmetry be spontaneously broken by a vacuum expectation value of at least one right-handed sneutrino. In a previous paper, we presented the results of a renormalization group analysis showing that B-L gauge symmetry is indeed radiatively broken with a B-L/electroweak hierarchy of O(10) to O(10^{2}). In this paper, we present the details of that analysis, extending the results to include higher order terms in tan[beta]^{-1} and the explicit spectrum of all squarks and sleptons.Comment: 60 pages, 6 figure

Gluon production on two centers and the effective action approach

Application of the effective action formalism is studied for processes in which the reggeons may split. It is shown that the gluon production on two centers is described by the contribution of the Reggeon-to-two-Reggeons-plus-Particle vertex supplemented by certain singular contributions from the double gluon exchange. The rules for longitudinal integrations are established from the comparison to perturbative QCD amplitude. Convenient expressions for application to the inclusive gluon production are derived.Comment: 15 pages, 7 figures; some misprints corrected; submitted to Eur.Phys.Jour.

Exclusive photoproduction of hard dijets and magnetic susceptibility of QCD vacuum

We argue that coherent production of hard dijets by linearly polarized real photons can provide direct evidence for chirality violation in hard processes, the first measurement of the magnetic susceptibility of the quark condensate and the photon distribution amplitude. It can also serve as a sensitive probe of the generalized gluon parton distribution. Numerical calculations are presented for HERA kinematics.Comment: 4 pages, 4 figure

Distribution of interference in random quantum algorithms

We study the amount of interference in random quantum algorithms using a recently derived quantitative measure of interference. To this end we introduce two random circuit ensembles composed of random sequences of quantum gates from a universal set, mimicking quantum algorithms in the quantum circuit representation. We show numerically that these ensembles converge to the well--known circular unitary ensemble (CUE) for general complex quantum algorithms, and to the Haar orthogonal ensemble (HOE) for real quantum algorithms. We provide exact analytical formulas for the average and typical interference in the circular ensembles, and show that for sufficiently large numbers of qubits a random quantum algorithm uses with probability close to one an amount of interference approximately equal to the dimension of the Hilbert space. As a by-product, we offer a new way of efficiently constructing random operators from the Haar measures of CUE or HOE in a high dimensional Hilbert space using universal sets of quantum gates.Comment: 14 pages revtex, 11 eps figure

Fluctuations and the QCD phase diagram

In this contribution the role of quantum fluctuations for the QCD phase diagram is discussed. This concerns in particular the importance of the matter back-reaction to the gluonic sector. The impact of these fluctuations on the location of the confinement/deconfinement and the chiral transition lines as well as their interrelation are investigated. Consequences of our findings for the size of a possible quarkyonic phase and location of a critical endpoint in the phase diagram are drawn.Comment: 7 pages, 3 figures, to appear in Physics of Atomic Nucle